The Transformation and Expression of Gene GalUR of Apple and Transformation Gene HS into Alfalfa and Salt-resistant Research of Different Variety Alfalfa
|Keywords||Malus robusta GalUR gene alfalfa HS gene salt-resistant|
The ascorbic acid （VC） that is rich in fresh fruits and vegetables, is called the vitamin C（ L-ascorbic acid, AsA）, which is a water-soluble vitamin for preventing and curing bad blood. It is an indispensable and tiny nutrition for human being.The body can’t synthesize vitamin C for human beings because of no the key enzyme-Gulose Lactone Oxydase. People have to absorb nutrition from diet for physiological needs. So the vitamin C in plants is the main source for needs of human beings. The newest research indicated that the normal human body essential vitamin C content is every day 200-400mg even higher. However, the contents of vitamin C in majority crops is in low level. Therefore the purpose is cultivating the more vitamin C of content crops for a long time in the future. At the same time, vitamin C in plants play an important role in many aspects such as anti-oxidized and elimination free radical, photosynthesis and light protection, cell growth and fission, participating hormones synthesis and signal transmission and so on（Conklin,2001）. For this reason vitamin C also was related to the plant oneself existing.The apple is one of the four greatest fruits in the world, which is the head regardless of in the culturing area and the yield in China. But the apple vitamin C content in the apple is very low. Therefore, if the apple of the more content vitamin C can be cultivated, not only may make its nutritional value to advance, moreover may enhance the apple’s itself the resistance,and is suitable for planting in saline-alkali land.The alfalfa （Medicago sativa） is the present commonly used green manure plant, often cultivated as the orchard green manure plants, which can improve the orchard soil poor condition and the orchard of micro climate. In order to improve and develop the saline-alkali land, transformation the anti-salt gene into the selected the anti-salt alfalfa variety, is not only improving fruit tree’s production and increasing the farmer’s income, more over carried on as the forage grass feeds to develop sideline. That is significant for making full use of the saline-alkali land in Bohai Wan Area to develop agriculture and improve the environment and bring about economic income for farmers.In this research GalUR gene which affect ascorbic acid synthesizing and metabolizing was transformed into Malus robusta and HS gene which adjusting bears resistance gene expression such as salty gene, drought resistance gene, anti-oxidized gene into alfalfa （M sativa） variety LongMu801 by transgenic engineering technology, and analyzed the FRO2 gene expression in transgenic and non- transgenic apple, discussed the relationship Fe2+ and ascorbic acid. The result is as follows:1. Using transformation method with Agrobacterium tumefacious, GalUR gene which affect ascorbic acid synthesizing and metabolizing has been transformed to M. robusta which is the fine apple rootstock of North, it has obtained a large number of transgenic Malus robusta. The experiment proved density of herbicides was 5mg/L which choose from GalUR gene transform M. robusta; with stem of destroying growing point as explants, it has a high translate ratio.2. The GalUR gene expression in apple was analyzed, the result was obtained: non-Fe2+-stressing could induce the expression of GalUR gene in apple leaves; the expression of GalUR gene in apple leaves had no difference in different apple variety; the expression of GalUR gene ehanced because of FRO2 gene transformation, but was repressed due to non- Fe2+-stressing. Therefore, the result showed the iron content was related to ascorbic acid. The expression GalUR gene was different in different parts and different organs of apple, the GalUR gene expressed from strong to weak: the expression in the fruit was stronger than in the leaf for untransgenic apple; the expression in the leaf was stronger than in the root for the transgenic apple.3. According to salt-stressing research and integrated weighing analysis of 8 alfalfa （M. sativa ） variety, the result showed the variety WL323, LaoBo was strongest in salt-resistent for level 1; next is Long Mu, QingLai for level 2; ChuangXin, MuXuWang for level 3; ZhongMu for level 4; HuangHou was worst for level 5.4. Transforming HS gene, which adjusting bears resistance gene expression such as salty gene, drought resistance gene, anti-oxidized gene into M. sativa. It has obtained a number of transgenic alfalfa. The experiment proved density of herbicides was 4mg/ml which choose from HS gene. The high-efficient transformed system to alfalfa had set up. The high callus rate and regeneration rate for alfalfa medium was MS+2,4-D0.8mg/L+KT2mg/L and MS+BA 4mg/L.